hurtling bones
In his fall, Urizen is disorganized and chaotic. The structure of his being and his world, his skeleton, are separate bones (forms) hurtling through the enclosure he has created out of Eternity.
bound every change
Los binds Urizen's hurtling parts and inchoate forms into a skeletal structure capable of being fleshed out. See the design on Plate 8
stony sleep
In his sleep, Urizen has become like a planet, which is shaken by earthquakes and volcanic eruptions as the geological ages pass. See 6.7 and also see Plate 9 for a depiction of a Urizenic figure entrapped in stone.
Beating
Los continues his work of giving form to Urizen's changes. The design on Plate 10 depicts Los struggling with the stony Urizen.
dividing / The horrible night into watches
Los divides Urizen's endless night into periods of attentiveness, dividing night into "day" (attentiveness, being on watch) and "night" (rest from the watch).
prolific delight
The satisfaction Urizen had in creation and procreation recedes and is lost more and more. See Ahania's speech in The Book of Ahania, 4.52-5.47.
dark secresy hiding
Urizen hides his pleasure in creation and procreation even from himself. He represses his creative activity in making the world and denies it.
dark bellows; / And turn'd restless the tongs; and the hammer
Los is often depicted as a blacksmith who takes inchoate materials and vague musings and out of them makes a concrete form.
forging chains new & new / Numb'ring with links. hours, days & years
Los creates chains of precise temporal measurements with which to bind Urizen into time.
bounded
Thought is measured by time and bound down by the chains Los forged out of the changes of Urizen.
Forgetfulness, dumbness, necessity!
Urizen forgets Eternity and is no longer able to converse with the other Eternals. Stevenson notes: "he is bound by the chains of inevitable cause and effect" (257n). He has forgotten that the laws of necessity that govern his world are his own invention.
inchain'd
Urizen is chained down into concrete form by the chains Los forged from his inchoate thoughts. The chains are Urizen's body, forged in seven dreadful ages.
first Age
This age is the first age or day of the seven ages of creation of Urizen's fallen body and fallen world (see Genesis 1). The skull, "a roof shaggy wild" (10.33) encloses his brain and "vast spine" (10.37), shooting out ribs, encloses "all his nerves of joy" (10.41). The skeleton being formed here makes Urizen incapable of feeling "prolific delight" (10.12) and starts to make his senses inflexible and unable to perceive eternity.
a state of dismal woe
The passage of each age of creation finds "a state of dismal woe" rather than one of wonder or joy. The horror of Urizen's self-inflicted sufferings caused by the chains of his own ideas become evident as the body of these thoughts become manifest as his body and the body of his world.
second Age
In this second age or day of creation, Urizen's heart and the "ten thousand branches" (11.6) of his circulation system are created.
third Age
In the third age or day of creation, Urizen's eyes, "two little orbs / And fixed in two little caves" (11.13-14), are created. The flexibility of the sense of sight is limited to orbs and enclosed in a caves so that it no longer can perceive Eternity. The third through the sixth age of creation see the limitation and shrinking of the senses of sight, sound, smell, taste. Touch was limited in the first age.
fourth Age
In the fourth age of creation, Urizen's sense of hearing is petrified into two ears.
fifth Age
In the fifth age of creation, Urizen's sense of smell is limited to "Two Nostrils bent to the deep" (13.1). The downward bent of this sense suggests the way Urizen has turned inward.
sixth Age
In the sixth age of creation, Urizen's taste is channeled into the thirst and hunger of the belly, throat, and tongue. The "craving Hungry Cavern" (13.6) symbolizes the unfulfilled desires that will dominate the creatures of this fallen world.
seventh Age
In the seventh Age of creation, Urizen's body is complete, and he is enraged and howls in dismay at what has happened to him. The imagery suggests the struggles and howling of a new born infant. God is not seeing his work as good or resting on the seventh day and sanctifying it. See Plate 22 for a depiction of the fully bound and formed Urizen.